How to choose
What's worth knowing before you buy: running costs, sizes, differences between technologies and which option suits your case. Straight answers, no padding.
16 topics · See all guides with products →
Appliances
- How much electricity does an air conditioner use per hour? A 12,000 BTU split uses between 0.9 and 1.4 kWh per hour depending on its efficiency, but only while the compressor is working. That's the key: a conventional unit switches on and off at full power, while an inverter lowers its output once it reaches temperature and so uses considerably less over long sessions.
- How many litres of fridge do I need? The practical reference is about 100 to 150 litres for the first two people, plus around 50 per additional person: 250 to 300 litres for one or two people, 350 to 400 for a family of four, and 450 or more for five or if you cook a lot at home. Before deciding, measure the gap where it goes, because a fridge that won't fit through the door is the most expensive mistake.
- How many watts of microwave do I need? For normal use — reheating food, defrosting, making a coffee — between 700 and 900 watts is plenty. Those of 1000 watts or more heat faster and more evenly, useful if you cook a lot in the microwave, but they aren't necessary for typical use. More important than the watts for most people is the size in litres, which decides which containers fit.
- Is a dishwasher worth it? Contrary to what many believe, a modern dishwasher uses considerably less water than washing by hand under a running tap, and it washes at a higher temperature, so it sanitises better. It's worth it especially with three or more people or if you cook a lot. The downside is the cost of the machine, that it takes up space, and that you have to load it well for it to wash properly.
- What washing machine capacity do I need for my household? The practical rule is about 1.5 to 2 kg of capacity per person: 6 kg for one or two people, 7 to 8 kg for a family of three or four, and 9 kg or more for five or if you wash bulky items like duvets. But the kilos aren't the only thing: the spin RPM decides how damp the laundry comes out.
- How many BTU do I need for my room? The base rule is 200 BTU per square metre (50 frigorías) in a normal room: 9000 BTU for 45 m², 12,000 BTU for 60 m². Add 20-30% if the room gets direct sun, has large windows, an uninsulated roof, or is on the top floor.
- How much does an electric heater cost to run per hour? An electric heater uses exactly its rated power: a 2000 W unit uses 2 kWh for every hour it runs at full output. To find the cost, multiply the kW by the hours of use and by the price per kWh printed on your electricity bill.
- Spin dryer vs. tumble dryer: what's the difference? A spin dryer does NOT dry with heat: it spins at high speed and pulls water out by centrifugal force, so clothes come out damp but ready to hang and dry far faster. A hot-air (tumble) dryer really does dry: clothes come out ready to put away, but it costs more, is bigger and uses considerably more power.
- Tank or tankless water heater: which one should I get? A tankless heater heats water on demand and never runs out, but flow drops if you open two taps at once. A storage heater keeps a tank of already-hot water: it holds pressure across several taps simultaneously, but once it's empty you wait for it to reheat. For one or two people with one bathroom, tankless; for a family with more than one bathroom, a tank.
Computing
- What WiFi router do I need for my home? For a flat or a small house, a dual-band router is enough. For a large house, two storeys or thick walls, a mesh system of several nodes beats a single router, because there the problem isn't power but coverage. And if you use the router your provider left you, replacing it usually improves the signal noticeably.
- How much RAM do I need in a laptop? For work, 16 GB is today's reasonable minimum: a browser with several tabs, a video-call app and a spreadsheet already use 7 to 8 GB. With 8 GB you'll always be at the limit; 16 GB keeps the laptop comfortable for years and is the upgrade with the best price-to-benefit ratio.
TV and Video
- How many lumens does a projector need? In a fully dark room, 1000 to 1500 ANSI lumens is enough. With some ambient light you need 2000 to 3000, and to watch in daylight with the blinds open you need 3500 or more. Careful: budget projectors advertise 'LED lumens' or 'source lumens', which run 3 to 5 times higher than real ANSI figures.
- What's the difference between LED, QLED and OLED? LED and QLED are the same underlying technology (an LCD panel lit from behind); QLED adds a quantum dot layer that gives it more brightness and more vivid colour. OLED is something else entirely: each pixel makes its own light, so it can switch off completely and achieve perfect blacks and a contrast neither of the other two can match.
